Concrete mixer



Jan. 12, 1937. J; E. BUSHNELL ET AL 2,067,826

CONCRETE MIXER Filed Sept. 15, 1932 6 Sheets-Sheet 1 Jan. 12, 1937.. J. E. BUSHNELL El AL CONCRETE MIXER Filed Sept. 13, 1932 6 Shets-Sheec 2 Jan. 12, 1937. BUSHNELL ET AL 2,067,826

CONCRETE MIXER Filed Sept'. 15, 1952 e Sheets-Sheet s Jan. 12, 1937. J. E. BUSHNELL ET AL 0 6- CON-CRETE MIXER Filed Sept. 15, 1932 6 Sheets-Sheet 4 I wembn yla 655 273 1937- J. E. BUSHNELL El AL 67,826

CONCRETE MIXER Filed. Sept. 13, 1932 6 Sheets-Sheet 5 Jan. 12, 1937. J. E. BUSHNELL ET AL 2,067,826

- CONCRETE MIXER Filed Sept. 15, 1932 6 Sheets-Sheet 6 Patented Jan. 12, 1937 STATES PATENT OFFICE CONCRETE MIXER Application September 13, 1932, Serial No. 632,878

8 Claims. (01. 83-73) The present improvements relate in general, to concrete mixing apparatus and in particular, to means and methods for speeding up and increasing the output of a mixer unit.

It is common practice to specify that the in-- gredients of each batch of concrete, be mixed for a certain minimum length of time to insure thorough mixing. This time element naturally limits the number of batches which can be mixed by one unit in a day. A primary object of the invention therefore, is to permit a greater number of batches of concrete to be mixed in a day but to mix each one for the same length of time as heretofore.

A further object is to provide a novel device which will permit uninterrupted mixing and discharge of batches of concrete.

Another object is to provide equipment which will be automatic in operation.

A further object is to provide.a. novel type of mixing drum, having a plurality of chambers, whereby a batch may be mixed in one chamber, while the other is being charged, whence both chambers are separately mixing whole batches. Another object is to provide a dual chamber drum wherein one batch may be mixing while another batch is being discharged.

Other objects include the provision of novel methods and details of construction, apparent upon reference to the accompanying specification and drawings, in which- Figure 1 is a longitudinal section through the mixing drum illustrating one embodiment of the improvements;-

Figure 2 is a cross section through the inner chute only;

Figure 3 is an end elevation of the discharge end of the mixer;

Figure 4 is a reversed side elevation of the discharge chute and operating means therefor;

Figure 5 is a side elevation of the operating means for the inner chute;

Figure 6 is a top plan view of the control unit for the skip hoist;

Figure '1 is a side elevation of the parts shown in Fig. 6;

Figure 8 is a front elevation of the camdiscof the control unit;

Figure 9 is a side elevation of the mixer showing diagrammatically the entire control mechanism;

Figure 10 is a view similar to Fig. 9 illustrating a modified arrangement.

Upon reference to the drawings, the rotary mixing drum I is provided with riding rings 2 upon which the drum revolves, being supported on a set of four hearings or supporting rollers (not shown) as is common in the art. The drum is driven by a suitable power unit P, through gearing in mesh with ring gear 3 fixed 5 about the circumference of the drum.

As illustrated, the drum is provided with the usual charging inlet 4, and discharging outlet 6 while a partition I is disposed between the inlet and outlet for dividing same into two compartments or mixing chambers 8, 9. The aggregates to be mixed, may be admitted to chamber 8 through spout 5 either by an overhead storage bin, from a pivoted skip such as 44, or in any other convenient manner.

Each chamber 8 and 9 is provided with conventional mixing bladesfla and 9a, well known in the art, so that the aggregates are mixed, first in chamber 8 and, after discharge through partition I, then in chamber 9, whence they are discharged through outlet 6. The total of the mixing periods of a batch in the two chambers amounts to the interval prescribed in the speciflcation for the particular work.

Communication between chambers 8 and 9 is aflorded through opening it! in partition 1, and

the transfer of a batch from the first chamber into the second chamber is preferably accomplished, in the present embodiment, through the medium of chute ll, although other agencies may be provided to effect the transfer, without departing from the scope of the invention. In the illustrated embodiment, a pivoted chute is provided whereby the aggregates in chamber 8 are deflected away fromv opening l0, preventing entrance into chamber 9, so long as the chute is in full line position (Fig. 1). When moved to dotted line position, the chute causes the discharge of the materials from chamber 8 into chamber 9. Obviously a revolving or longitudinally slidable chute, readily movable into corresponding positions, may be supplied in place of a tiltable chute.

After the niixing period in chamber 9 has lapsed, the batch may be discharged, either manually or automatically by moving chute i2 to dotted line position (Fig. 1), whence the aggregates discharge through chute l3 into any suitable receptacle. So long as the chute l2 remains in full line position, no discharge will take place.

A pair of beams I], extend longitudinally through drum l, protrude through openings 4 and 6 and may be secured to the frame work is of the mixer at either end thereof. If desired, these beams may stop short of the, charging 55 opening of the drum and may be fastened to the charging chute 5, \just inside the drum. Upon reference to Figs. 1 and 2, the chute II is preferably fixed to cross shaft I4 which is journalled in bearings I5 and I6 secured to beams I1. A crank I9 fixed adjacent the end of shaft I4 may be moved from full to dotted line position (Fig. 1) for correspondingly swinging chute I I.

Means for moving chute II are provided by link 20, pivoted to cranks I9 and 2I, the latter being fixed to shaft 22, outside of the mixer drum. It is noteworthy, that the right hand beam I1 (Fig. 2) is provided with an auxiliary plate "A, which forms a sealed, closed chamber I1B for housing the elements I9 and 20 and protecting them from the entrance of concrete, etc. Bearing I5 is also sealed against interfering materials.

Referring to Fig. 3, it is seen that shaft 22 is actuated through a series of elements 23 to 26 by a power driven mechanism 21, similar to that described and claimed for operating chutes in the patent to Shafer No. 1,415,411, issued May 9, 1922. The details of this construction are not illustrated here as they form no part of the present invention. For purposes of this description, it is sufficient to state that upon withdrawal of arm 21A from notched disc 21B (Fig. 3) the mechanism 21, driven by suitable gearing (not shown) etc. in mesh with ring gear 3, serves' through the connections previously mentioned, to swing chute II.

Referring to Fig. .3, the mounting and actua ing means for chute I2 is illustrated, since certain of these elements have been omitted in Fig. 1 to avoid confusion.- Chute I2 is fixed on shaft 28, iournalled in bearings 29 mounted on frame I8. Shaft '26" isconnected to another chute operating mechanism 34 (similar to mechanism 21 above-mentioned) by means of elements 30, 3|, 32 and 33. This mechanism 34 is likewise driven from ring gear 3, uponawithdrawal of arm 34A from notched disc 343. As is well known, the withdrawal of arms 34A and 21A, permits the engagement of clutches, as will be seen upon reference to said patent.

The chute operating devices 21 and 34 may be operated by either manual or automatic (me- Referring to Fig. 9, the loading skip 44 is seen to be of the double pivot type. having pivots at a and b, as set forth in the patent to Faber No. 1,767,443, issued June 24, 1930, although any other mounting forthe skip may be employed. The skip is elevated and lowered through cable 0 and sheaves s, being controlled by drum 43, having a hoist clutch 43A for deriving power from power shaft 43 from unit P, for elevating the skip, and a brake means 433, for lowering same.

The drum 43 is mounted on the mixer drive shaft 48, which is journalled in bearings, one of which is shown at 49 (Fig. 6). Any suitable mechanism may be employed for engaging the clutch 43A and elevating the skip 44, as is common in the art. A conventional showing in Figs. 6 and '1, is found where shaft 50 is provided for this purpose. This shaft, 50 has arm 5| keyed thereto, which may be attached at 5IA to a hand lever (not shown). A bracket 52 on arm 5|, carries roller 53 disposed in the path of travel of cam 65 on disc 63.

A timing mechanism 42 includes clutch member 55, slidable on a. key on shaft 48 and adapted to be engaged with pinion 54, loosely mounted thereon. Clutch 55 is moved by means of trunnion ring 56, engaging yoke 51, attached to shaft 58 journalled in bearings on frame 59. As illustrated, pinion 54v meshes with a gear train 60, H, the latter gear being keyed to shaft 62, whereby a relatively slow motion is imparted to said shaft. A disc 63, keyed to shaft 62, is provided in rim 63A, with notch 64, and with an adjustably mounted cam 65. The cam may be located at any point about the periphery of the disc (Fig. 8) so that the distance from notch 64 may be varied.

A lever 66, carrying roller 61, is releasably held by spring 68, with the roller riding on the rim 63A of disc 63. A rod 69-, attached to lever 66,- extends to and is connected with lever 10, keyed to shaft 56. The urge of spring 68, tends to move levers 66 and 10 in a clockwise direction, for disengaging clutch 55. A cable or rod 4I is attached to lever 66 for overcoming the spring and for pulling said levers counterclockwise (Fig. 7) for engaging clutch 55, said cable being attached to lever 31 (Figs. 5, 9)

- Referring again to Fig. 9, a lever 46, operable by lug 45 on the pivoted skip frame, is connected by cable 41 to arm 21A for starting the operation of chute operating mechanism- 21, for moving chute II. A batch meter timing mechanism 1|, is provided for timing the mixing interval. An actuating rod'90', is connected to the batch meter and has a free end protruding for resetting the meter H, by skip 44, during the final portion of its movement to discharge position. A connection 9| is operated by batch meter 1I, when rod is actuated, for locking manual lever I00 against actuation.

Upon reference to Figs. 5 and 9, it is seen that lever 31 has cables M and 39 attached thereto, the latter leading to and connected with arm 34A for actuating chute operating mechanism 34, for swinging chute I2. A trip 35, fixed for rotation with shaft 22 moves lever 31 from full to dotted line position, the spring 38, returning the lever to full line position. A dog 36, pivoted on lever 31, so as to freely move to dotted line position (Fig. 5) permits trip 35 to return beyond lever 31 in a counterclockwise direction. An, operators discharge control lever I00 is also attached to cable 39 for manually actuating same. This lever I00 is locked against untimely operation by connection 9| from the batch meter H, as aforementioned.

A foot pedal 93 with cable 94 attached to arm 21A provides for manually starting the operation of chute II. A conventional clutch release rod 95 is actuated by the skip, for suitably releasing hoist clutch 43A when the skip approaches the end of its upward travel.

In describing the cycle of operation, it will be assumed that batches of concrete are being mixed in chambers 6 and 9. When the mixing interval, set on batch meter or timing mechanism H, for. the mixture in chamber 9, has

transpired, the-rod 9I is operated by the batch meter, thereby unlocking lever I00, which may now be manually operated by the operator. This withdraws arm 34A from notched d isc 34B permitting. power discharge mechanism 34 to swing chute I2 to dotted line, discharge position 75 (Fig. 1), thereby effecting discharge of the batch from chamber 9.

At this stage in the cycle, the operator depresses the foot pedal 93 to transfer the batch being mixed in chamber 8 to chamber 9. The time for doing this is at the option of the operator, who may actuate the pedal as soon as he observes the discharge from chamber 9 completed and sees that the truck for loading the skip is clear thereof. Actuation of pedal 93 causes inner chute II to move from full to dotted line (discharge) position, and the contents of chamber 8 are emptied into chamber 9. During this operation, the movement of shaft 221 causes trip 35 to rock lever 31, whereby mechanism 34 is again actuated, and outer chute I2 is swung to full line (non-discharging) position.

As lever 31 is rocked by the above described action, cable 4I is pulled thereby setting the timer 42 in motion. Upon reference to Figs. 6 and 7, it is seen that a pull on member H in opposition to spring 58, withdraws roller 81 from notch 64 in disc 63, and rocks lever 10, engaging clutch 55. Normally roller 51 rests in notch 64, and clutch 55 is disengaged. Power from shaft 48 (derived from unit P) causes disc 83 to revolve very slowly carrying cam 65 toward roller 53 disposed in its path. After the proper interval, predetermined by suitable location of cam 65 with respect to notch 64, roller 53 is encountered by said cam, and the roller is forced outwardly by continued rotation of the cam. As illustrated, the roller rides .up in the cam 65 (Fig. 7) and shaft 50 is thereby rocked causing hoist clutch.- 43A to be engaged, whereby elevation of skip44 is begun.

- The clutch 43A is of the conventional self locking type and remains engaged until the skip completes its travel and moves knock-out lever 95. Obviously, continued rotation of disc 83, causes roller 53 to ride down off of cam 65, and upon completion of the 360 revolution of the disc, roller 81 again enters notch 64. Clutch 55 is thereby released and the timer 42 ceases to function.

An additional batch of dry aggregatejn skip 44, is elevated and discharged into chamber 8. As described, the upward movement of the skip causes parts 45 and 46 to actuate cable 41, for again operating inner chute II, and returning it to full line (non-discharging) position. Final upward movement of the skip actuates members 90 and 95. The former sets the mixing interval on the meter 1| and locks handle I00 against untimely operation. Member 95 releases clutch 43A thereby preventing further elevation of the skip, whereupon the automatic brake 43B holds the skip in elevated position whence it may be lowered by manually releasing the brake.

This completes the cycle of operation, which may be repeated when the batch meter ll again releases handle I00.

Cam 65 has a steep slope on its rear face to give a quick release from roller 53 in order to permit the operator to manually disengage the skip after it has started to rise, if the necessity should arise.

Disc 03 has a series of holes through any of which cam 65 can be bolted. The distance in the direction of rotation that cam 65 is from notch 54 determines the time which elapses from the moving of chute II to the start of raising of the loading skip t4 and in this manner just suflicient time can be made to elapse to permit the contents of cber.8 to be transferred to chamber 9 before the new batch'enters chamber 8. The timing mechanism II acts to insure the materials remaining in the mixing drum a specified length of time.

Upon reference to the modified arrangement illustrated in Fig. 10, it is seen that the pedal 83 and cable 94 are dispensed with,'so that the I operation of chute II follows that of chute I2, without depending upon the operator. In this form, the batch meter or timing mechanism I'll is of special construction, which forms the subject matter of a separate application.

The shaft 28 (Fig. 10) is operatively connected tobatch-meter I'll by rodl05, while rod I06 extends downwardly to actuate power operated means I01, which in turn is connected to chute ;:I operating mechanism 21, and 21A by cable When operator's handle I00 has been moved, and chute I2 is actuated by mechanism 34, this movement of shaft 28, through shaft I05, sets in motion another part of meter Ill, and after a predetermined interval (sufilclent to .allow chamber 9 to be discharged), the rod I06 is actuated by the timer. This permits control device I0'l to pull cable I08 and thereby actuate chute control means 21 whereby inner chute II is moved to discharge (dotted line) position, to

transferthe batch in chamber 8 to chamber 9. The remainder of the cycle is the same as that described with respect to Figs. 1 to 9. It is therefore seen, in the modified form, that the operahalf or one and two thirds.

It is understood that the present invention has been described as applied to a. paver unit,

although it is adaptable to any type of concrete. mixing apparatus.

Among other details of importance, it is noteworthy that the middle chute II is positioned so as to be free of the port I0, when it is in non-discharging (full line) position. This insures against accidental or inadvertent transfer of aggregate from one chamber to the other, since chute II deflects the aggregate away from chamber 9.

Various modifications of the improvements may be made without departing from the scope and purview of the invention.

We claim:

1. A concrete mixing and distributing machine comprising a hollow cylindrical drum defining a mixing chamber and having a plurality of mixing compartments therein and mounted for rotation, means for rotating the same, said drum having charging and discharging openings therein, batch charging and discharging devices adjacent said openings respectively and means for operating the same to charge the drum with a batch of unmixed aggregates and discharge said batch therefrom in mixed condition through said openings, mixing devices in said compartments mounted on and to rotate with said drum for mixing the said batch, a partition in the interior of said chamber dividing the same into said plurality of compartments and having an opening therein through which the aggregates may be transferred from one compartment to the other, transferring means in said chamber including a chute-like part, said 'means being movable to transferring and non-transferring positions and while in non-transferring position being operative in one compartment and inoperative to either cause or, in its combination and arrangement with respect to the mixing means, permit movement of aggregates from one compartment to the other and being out of frictional contact either directly or through the aggregates with said partition.

2. A concrete mixing and distributing machine comprising a hollow cylindrical drum defining a mixing chamber and having a plurality of mixing compartments therein and mounted for rotation, means for rotating the same, said drum having charging and discharging openings therein, batch charging and discharging devices adjacent said openings respectively and means for operating the same to charge the drum with a batch of unmixed aggregates and discharge said batch therefrom in mixed condition through said openings, mixing devices in said compartments mounted on and to rotate with said drum for mixing the said batch, said mixing devices constructed and arranged to move said aggregates in two directions longitudinally and to move them radially of the chamber and extending substantially throughout the length thereof, a partition in the interior of said chamber dividing the same into said plurality of compartments and having an opening therein through which the aggregates may be transferred from one compartment to the other, transferring means in said chamber including a chute-like part, said means being adjustable to transferring and non-transferring positions within the drum and while in nontransferring positions being inoperative to either cause or, -in its combination and arrangement with respect to the mixing means, permit movement of aggregates from one compartment to the other and being out of frictional contact either directly or through the aggregates with said partition.

3. A concrete mixing and distributing machine comprising a hollow cylindrical drum defining a mixing chamber and having a plurality of mixing compartments therein and mounted for rotation, means for rotating the same, said drum having charging and discharging openings therein, batch charging and discharging devices adjacent said openings respectively and means for operating the same to charge the drum with a batch of unmixed aggregates and discharge said batch therefrom in mixed condition through said openings, mixing devices irrsaid compartments mounted on and to rotate with said drum for mixing the said batch, said mixing devices constructed and arranged to move said aggregates in two directions longitudinally and to move them radially of the chamber and extending substantially throughout the length thereof, a partition in the interior of said chamber dividing the same into said plurality of compartments and having an opening therein through which the aggregates may be transferred from one compartment to the other, transferring means in said chamber, including a chute-like part, said means comprising a concave concrete receiving and discharging member wholly within the drum movable to transferring and non-transferring positions and while in both positions being inoperative to either cause or, in its combination and arrangement with respect to the mixing means, permit movement of aggregates from the second compartment to the other and being out of frictional contact either directly or through the aggregates with said partition.

4. A concrete mixing and distributing machine comprising a hollow cylindrical drum defining a mixing chamber and having a plurality of mixing compartments therein and mounted for rotation, means for rotating the same, said drum having charging and discharging openings therein, batch charging and discharging devices adjacent said openings respectively and means for operating the same to charge the drum with a batch of unmixed aggregates and. discharge said batch therefrom in mixed condition through said opening, mixing devices in said compartments mounted on and to rotate with said drum for mixing the said batch, a partition in the interior of said chamber dividing the same into said plurality of compartments and having an opening therein through which the aggregates may be transferred from one compartment to the other, transferring means in said chamber including a chute-like part, said means being movable to transferring and non-transferring positions and while in non-transferring position being inoperative to either cause or, in its combination and arrangement with respect to the mixing means, permit movement of aggregates from one compartment to-the other and being out of frictional contact either directly or through the aggregates with said partition and said trans-- ferring means being operative while in no-transferring position to direct away from said lastnamed opening and effect mixing movement of the aggregates. 5. A concrete mixing and distributing machine comprising a hollow cylindrical drum defining a mixing chamber and having a plurality of mixing compartments therein and mounted for rotation, means for rotating the same, said drum having charging and discharging openings therein, batch charging and discharging devices adjacent said openings respectively and means for operating the same to charge the drum with a batch of unmixed aggregates and discharge said batch therefrom inmixed condition through said openings, mixing devices in said compartments mounted on and to rotate with said drum for mixing the said batch, a partition in the interior of said chamber dividing the same into said plurality of compartments and having an opening therein'through which the aggregates may be transferred from one compartment to the other, transferring means in said chamber including a chute-like part, said means being movable to transferring and non-transferring positions and while in non-transferring position being inoperative to either cause or, in its combination and arrangement with respect to the mixing means, permit movement of aggregates from one compartment to the other and being out of frictional contact either directly or through the aggregates with said partition, a fixed support for transferring means inside the drum, operating means connected therewith inside the drum and extending to the exterior of the drum and protecting means for said operating means extending over the same and between such means and the upper part of the drum.

6. A concrete mixing and distributing machine comprising a hollow cylindrical drum defining a mixing chamber and having a plurality of mixing compartments therein and mounted for rotation, means for rotating the same, said drum having charging and discharging openings therein, batch charging and discharging devices adjacent said openings respectively and means for operating the same to charge the drum with a batch of unmixed aggregates and discharge said batch therefrom in mixed condition through said openings, mixing devices in said compartments mounted on and to rotate with said drum for causing longitudinal and angular movements of the aggregates and mixing the said batch, a partition in the interior of said chamber dividing the same into said plurality of compartments and having an opening therein through'which the aggregates may be transferred from' one compartment to the other, transferring means in said chamber and operating within one of said compartments including a chute-like part, said means being movable to transferring and nontransferring positions and while in non-transienring position being inoperative to either cause or in its combination and arrangement with respect to the mixing means, permit movement of aggregates from one compartment to the other and being out of frictional contact either directly or through the aggregates with said partition.

7. A concrete mixing and distributing machine comprising a hollow cylindrical drum defining a mixing chamber and having a plurality of mixing compartments therein and mounted for rotation, means forrotating the same, said drum having charging and discharging openings therein, batch charging and discharging devices adjacent said openings respectively and means for operating the same to charge the chamber with a batch of unmixed aggregates and discharge said batch therefrom in mixed condition through said openings, mixing devices in said compartments mounted on and to rotate with said drum for mixing the said batch, a partition in the interior of said chamber dividing the same into said plurality of compartments and having an opening therein through which the aggregates may be transferred from one compartment to the 'other, transferring means in said chamber and within one of said compartments including a chute-like part, said means being movable to transferring and non-transferring positions and while in non-transferring position being inoperative to either cause or in its'combination and arrangement with respect to the mixing means, permit movement of aggregates from one compartment to the other and being out of frictional contact either directly or through the aggregates with said partition, said charging, discharging and transferring means being arranged for timed operation, and a-batchmeter device for controlling said operation.

8. In an apparatus of the kind described, the combination with a single rotatable drum having charging and discharging openings therein, mixing devices therein and an interior dividing partition dividing said interior into compartments and having an opening communicating between the compartments formed thereby, of means for charging a batch of unmixed aggregates into the first compartment through said charging opening, means in one of said compartments out of frictional contact direct or indirect with said partition and including a concave part for automatically closing communication of aggregates between said first compartment and second compartment through the operation of and while said charging means is operating to charge said first compartment, means for automatically main-, taining said closure during a period thereafter while the said batch is being partly mixed in said first compartment, means for moving said closing means between the first and second compartments to cause the partly mixed batch to be discharged from said first compartment into said second compartment through said communieating opening, automatic means for closing other communication between said second compartment and the exterior thereof while the said partly mixed batch is being discharged from the first compartment into the second compartment and for a period thereafter while the same is being mixed in the latter, means for opening the discharging opening from the second compartment and causing the batch of mixed materials to be discharged therethrough while maintaining communication between the said compartments closed, automatic means for maintaining the last named closure while the said aggregates are being mixed in the second compartment and while a new batch of unmixed aggregates is being charged into the first compartment'and automatic means for carrying on said mixing operation in the second compartment and holding the aggregates therein during such charging operation and for a period thereafter, the said means being constructed and arranged to be operated successively in timed relation and continuously.

, JAMES E. BUSHNELL.

JOHN P. FABER. 

